Personal flotation devices are well known and for many applications, such as boating, are legislatively required to be worn by a boat user or carried aboard for use when necessary.
The types of flotation devices available include life jackets and vests as well as a wide range of inflatable clothing and potentially include items such as life rafts. Many approved life jackets are manufactured from buoyant foam type materials and are cumbersome to wear making many people reluctant to wear them.
An alternative flotation device is an inflatable life jacket however people such as those who fish from rocks or swimmers or surfers, who may well run the risk of drowning are unlikely to wear such devices. In particular, swimmers do not want the obstruction and drag of wearing such a device.
A difficulty which is associated with inflatable buoyancy devices is that a relatively bulky gas cylinder and valve mechanism is required to provide a given volume of gas, the gas customarily being Carbon Dioxide which is stored as a high pressure liquid in the cylinder. In addition many people who are not legislatively required to wear such garments for their particular water sport would not do so owing to the appearance of such garments.
It is known for children to wear inflatable devices on their bodies when learning to swim under supervision however these are usually not of a kind that could be deployed by an adult in an emergency.